There it is, the first Sea Ice Outlook of this year. The SIO is organized by the interagency "system-scale, cross-disciplinary, long-term arctic research program" SEARCH (Study of Environmental Arctic Change), and is a compilation of projections for the September 2013 Arctic sea ice extent, based on NSIDC monthly extent values. These projections are submitted by professionals as well as amateurs (public outlooks).Here's the summary for the June report:
With 23 pan-arctic Outlook contributions, an increase over the last two years (thank you!), the June Sea Ice Outlook projects a September 2013 arctic sea extent (defined as the monthly average for September) median value of 4.1 million square kilometers, with quartiles of 3.8 and 4.4 million square kilometers (Figure 1).
The consensus is for an increasing downward trend of September sea ice extent. We interpret the split of 2013 Outlooks above and below the 4.1 median to different interpretations of the guiding physics: those who considered that observed sea ice extent in 2012 being well below the 4.1 level indicates a shift in arctic conditions, especially with regard to reduced sea ice thickness and increased sea ice mobility; and those with estimates above 4.1 who support a return to the longer-term downward trend line (1979-2007). It is always important to note for context that all estimates are well below the 1979–2007 September mean of 6.7 million square kilometers.
And here's the figure showing all the projections (click for a larger version):
All in all a rather conservative outlook, but not as conservative as last year. Of course, the slow start to the melting season doesn't really inspire confidence for a more aggressive contribution.
These are the September minimums for the last 7 years (in millions km2, found here):
- 2005: 5.57
- 2006: 5.92
- 2007: 4.30
- 2008: 4.73
- 2009: 5.39
- 2010: 4.93
- 2011: 4.63
- 2012: 3.61
If you want to compare this outlook with those of previous years, there's an archive on the SEARCH home page (in the left hand bar).
Larry Hamilton has just posted his second Crowd-Source Prediction of Mean September Sea Ice, this post that is just a quick look at the first SEARCH SIO report. Larry writes:
The next SIO deadline is early July. You are all invited to submit, as comments to this post, your best guess for the mean September extent of Arctic sea ice (NSIDC). Your numerical prediction should be in the first line of the comment, followed by at least a sentence or two explaining the basis for your prediction — whether pure intuition, elaborate calculations, whatever you’ve got. Predictions are not bound by whatever you did or did not guess last month. As before, general discussion is welcome too.
So be sure toclick on Larry's post right now, read his in-depth analysis of the first SEARCH SIO, and share your prediction with everyone.